Effect of cetirizine on histamine-induced bronchoconstriction and bronchoalveolar cells.

The effect of the histamine H1 receptor antagonist (cetirizine) on histamine-induced bronchoconstriction and inflammatory cells in bronchoalveolar lavage fluid was studied in 12 healthy volunteers. In previous studies we have observed an increased number of inflammatory cells, albumin and hyaluronan in the bronchoalveolar lavage (BAL) fluid 24 h after an inhalation challenge test with histamine-chloride. In the present study certirizine blocked the histamine-induced bronchoconstriction but did not influence the cell counts in the bronchoalveolar lavage fluid. Our result suggests that the histamine-induced bronchoconstriction but not the recruitment of inflammatory cells in the BAL fluid is mediated by histamine H1 receptors.